The present invention pertains to a new automated approach toward forwarding a water main connection which as a result enables novel irrigation practices.
Movable sprinklers, including a series of nozzles mounted along a delivery pipe that moves laterally along a series of access valves, have been in use for decades. One approach has the movable delivery pipe stationary while irrigating. After irrigating, the delivery pipe is disconnected from the water main and moved forward to a successive access valve and then reconnected to the water main. However, it is highly preferable to slowly forward the delivery pipe during irrigation.
Many ways have been suggested to manually forward the connection after intervals of forward traveling irrigation. Manually forwarding a draggable hose is today""s common practice. Manual connection forwarding introduces undesirable costs, inefficiencies and operational limitations to what is otherwise the most desirable method of irrigation water application.
Many methods have been suggested to automate the forwarding of the supply main connection. Suggested methods found include: Engel U.S. Pat. No. 2,750,228; Hogg U.S. Pat. No. 3,281,080; Smith U.S. Pat. No. 3,381,893; Purtell U.S. Pat. No. 3,444,941; Rogers U.S. Pat. No. 3,463,175; Stafford U.S. Pat. No. 3,255,969; Nobel U.S. Pat. No. 4,295,607; and Nobel U.S. Pat. No. 4,274,584. All of these methods are very elaborate. Furthermore, all of these methods limit the delivery pipe to straight line travel only. Consequently, after completing an irrigation across a field, the delivery pipe must reverse travel the irrigated field in order to assume its original starting position.
U.S. Pat. No. 4,877,189 to Williams discloses a swing arm pivotably mounted to the water delivery pipe and a valve coupler mounted to the opposite free swinging swing arm end. Valve connection is made and the delivery pipe irrigates traveling the same distance found between successive access valves. The coupler is then disconnected from the valve and the free swing arm end, with coupler, is ground pivoted to the next valve where connection is again made. Delivery pipe travel results in rotation of the swing arm about the valve connection. This rotation feature also enables the swing arm and the water delivery pipe to be pivoted about a valve as an anchor to a similar position on the opposite side of the water main, representing a distinct improvement over the previous references. With Williams one length of water delivery pipe will suffice where previously two were required, greatly reducing equipment cost. Also, irrigation is circuitous and thus no backtracking is required.
The Williams apparatus offers many other distinct advantages over the previously mentioned references as well. Distance between valves is improved with Williams, reducing overall cost. In addition, simplified valve coupling as well as a unique approach to maintaining the delivery pipe aligned with the water main are evident.
The present invention serves to incorporate a number of improvements with the Williams apparatus greatly improving reliability, durability, and operating efficiency while reducing the sales price.
Williams incorporates a transporter for ground supporting and moving the free swinging end of the swing arm for travel between valves. It is advantageous to relocate the transporter so that during travel the access valve passes to the outside of the transporter rather than to the inside as suggested with Williams. It is also advantageous to improve the approach toward raising and lowering the transport wheels to eliminate a disruption of the ground surface as well as greatly lighten the required structure.
The valve coupler of Williams utilizes a set of tracks parallel to the swing arm length to allow the coupler directional alignment along the tracks during the coupling procedure as well as to facilitate straight line travel of the delivery pipe. These tracks may be improved by providing an overhang arrangement enabling much longer tracks and facilitating the aforementioned relocation of the transporter.
The Williams apparatus may be further improved by incorporating a sway inhibitor which provides great rigidity to the swing arm and maintains the tracks rectangularly configured relative to each other. The sway inhibitor thereby enables a greatly increased rate of transporter travel between valves. Typically, operation of the transporter requires a halt or diversion of water flow while a water supply pump remains in operation under a stressed or compromised condition. Therefore, increasing the rate of travel between valves reduces the stress or compromised condition to the pump.
For directional alignment perpendicular to the swing arm during valve coupling, Williams suggests moving the entirety of the swing arm apparatus via the ground surface. A further improvement is to provide an apparatus allowing coupler travel perpendicular to the swing arm length between the coupler and the tracks. Subsequently, loading on coupler and valve is greatly reduced when acting against the valve to facilitate alignment.
Typically all common day lateral move irrigators utilize one of three guidance systems to maintain the delivery pipe aligned with the water main. One method stretches a guide wire along the travel path. A second method buries a signal bearing guide wire along the travel path. For the third method, a small guidance ditch is dug along the travel path. The Williams apparatus offers an inherent less expensive way to maintain alignment between the delivery pipe and the water main and thus none of the above three options are required.
Williams suggests geographic positioning of the delivery pipe by measuring the angular alignment between the swing arm and the delivery pipe and by measuring the forward distance traveled by the delivery pipe. The appropriate position for the valve coupler along the tracks is then determined and the coupler position is then adjusted accordingly which serves to utilize the access valve as a positioning anchor. An improved approach utilizes the measured position of the coupler along the tracks and the measured forward travel direction of the delivery pipe to accurately maintain the delivery pipe a constant distance from the water main. Corrections are made by simply slightly turning the water delivery pipe toward or away from the water main as required to maintain the given distance from the main. The improved approach does not require measuring the forward distance traveled by the delivery pipe and more importantly eliminates the forces and resultant problems with utilizing the access valve as a positioning anchor.
U.S. Pat. No. 4,036,436 to Standal suggests adjusting the travel direction of a lateral moving water delivery pipe in accordance with the distance between a valve coupler and a delivery pipe at each successive engagement of the valve coupler to a water main access valve. Standal suggests that the water delivery pipe may be modified to travel while the coupler remains engaged to an access valve but gives no specific example of a mechanism for accomplishing this. Standal makes no reference to the more accurate navigation approach of measuring the travel direction of the delivery pipe and utilizing the measured travel direction in combination with the measured distance between valve coupler and delivery pipe to prescribe adjustments in the travel direction of the delivery pipe.
Williams suggests a telescoping conduit assembly to hydraulically connect the valve coupler to the swing arm. Water pressure in this arrangement will supply a large force toward extending the telescoping conduit, exerting a side force against the access valve as well as the water delivery pipe. Of further improvement, two conduit lengths pivotably connected together with one of the remaining ends pivotably connected to the valve coupler and the last end pivotably connected to the swing arm offer hydraulic connection between the coupler and the swing arm while eliminating the side force.
To the inventor""s knowledge, no one has suggested a measuring device to determine the relative vertical position between components of the connector apparatus and an access valve. The advantages of such a device include speeding travel between valves and minimizing clearances required between the connector apparatus and an access valve.
Selectively varying the discharge of water along the length of a water delivery pipe has been described in U.S. Pat. No. 5,246,164 to McCann. The McCann patent discloses a system for use with center pivot irrigation in particular and suggests the approach may also be applicable to laterally traveling irrigators. McCann fails to specify a way to geographically track the position of laterally traveling irrigators other than to suggest a sprinkler line position sensor. The present invention includes novel features of the previously disclosed approach toward navigating the delivery pipe which further offer an ability to geographically track the position of a laterally traveling irrigator.
In summary, lateral move sprinkler mounted water delivery pipes, adapted for continuous travel during water application, offer superior and uniform application properties while irrigating rectangular areas. These qualities are most desirable. Unfortunately, no affordable and reliable method of automatically connecting the traveling delivery pipe to a stationary series of access valves has been developed for market to date, severely restricting use of these systems.
The present invention provides unique features to the Williams connection approach. The resultant apparatus enables affordable and reliable automated connector forwarding for continuous travel lateral move sprinklers.